APA (7th ed.) Citation

Montessori, M., & Costelloe, M. J. (1976). The discovery of the child (5th printing.). Ballantine Books.

Chicago Style (17th ed.) Citation

Montessori, Maria, and M. Joseph Costelloe. The Discovery of the Child. 5th printing. New York: Ballantine Books, 1976.

MLA (9th ed.) Citation

Montessori, Maria, and M. Joseph Costelloe. The Discovery of the Child. 5th printing. Ballantine Books, 1976.